TY  - RPRT
TI  - An exposure meter for the electron microscope.
AU  - E H FREI
AU  - F L HIRSHFELD
PY  - 1951
DO  - 10.1063/1.1745897
UR  - https://pubmed.ncbi.nlm.nih.gov/14854366/
ID  - 14854366
ER  -